MySQL Memory Usage Verbose

Overview

Perl script to calculate MySQL max memory allotment.

Modified original code to search for cPanel defaults.

This version also give a more verbose output then the original.

Script

[perl,n]

1. !/usr/bin/perl
3. calculate mysqld memory consumption from my.cnf
4. usage: mysql-memory-usage /path/to/my.cnf [/path/to/mysqld]
6. $Id: mysql-memory-usage 228 2010-05-31 10:53:33Z schwenke $

my $mycnf= shift; $mycnf= "/etc/my.cnf" unless $mycnf; die "cannot read $mycnf\n" unless (-r $mycnf);

my $mysqld= shift; unless ($mysqld) { # find mysqld relative to mysql $mysqld= `which mysqld` or $mysqld= `which mysql` or die; chomp $mysqld; $mysqld =~ s(bin/mysql$)(libexec/mysqld); } die "cannot execute $mysqld\n" unless (-x $mysqld);

1. read configuration

my %conf; open M, "$mysqld --defaults-file=$mycnf --help --verbose |" or die; while (<M>) { # skip to parameter list last if (/^\-{5,} \-{5,}$/o); } while (<M>) { last if /^$/o; my ($var, $val)= split; $conf{$var}= $val; } close M;

1. static memory consumption

my $static= $conf{'key_buffer_size'} + $conf{'query_cache_size'};

1. has innodb

$static+= $conf{'innodb-buffer-pool-size'} + $conf{'innodb-log-buffer-size'} + $conf{'innodb-additional-mem-pool-size'} if (($conf{'innodb'} eq 'TRUE') or ($conf{'innodb'} eq 'ON')); print "Static Memory Consumption\n"; printf " %-10s key_buffer_size\n", p($conf{'key_buffer_size'}); printf "+%-10s query_cache_size\n", p($conf{'query_cache_size'}); if (($conf{'innodb'} eq 'TRUE') or ($conf{'innodb'} eq 'on')) { printf "+%-10s innodb-buffer-pool-size\n", p($conf{'innodb-buffer-pool-size'}); printf "+%-10s innodb-log-buffer-size\n", p($conf{'innodb-log-buffer-size'}); printf "+%-10s innodb-additional-mem-pool-size\n", p($conf{'innodb-additional-mem-pool-size'}); } printf "%-5s Total Static Memory\n\n", p($static);

1. per thread memory consumption

my $thread= $conf{'thread_stack'} + 2*$conf{'net_buffer_length'} + $conf{'read_buffer_size'} + $conf{'read_rnd_buffer_size'} + $conf{'sort_buffer_size'}; print "Per thread memory consumption\n"; printf " %-10s thread_stack\n", p($conf{'thread_stack'}); printf "+%-10s net_buffer_length 2x (%s)\n", p($conf{'net_buffer_length'}), p(2*$conf{'net_buffer_length'}); printf "+%-10s read_buffer_size\n", p($conf{'read_buffer_size'}); printf "+%-10s read_rnd_buffer_size\n", p($conf{'read_rnd_buffer_size'}); printf "+%-10s sort_buffer_size\n", p($conf{'sort_buffer_size'}); printf "%-5s Total Memory Per Thread\n\n", p($thread);

1. writes binlog

$thread += $conf{'binlog_cache_size'} if ($conf{'log-bin'} ne '(No'); printf " %-10s binlog_cache_size\n\n", p($conf{'binlog_cache_size'}) if ($conf{'log-bin'} ne '(No');

1. MyISAM repair thread(s)

my $repair= 0; if ($conf{'myisam-recover'} ne 'OFF') { $repair+= $conf{'myisam_repair_threads'} * $conf{'myisam_sort_buffer_size'}; print "MyISAM Repair Thread(s)\n"; printf " %-10s myisam_repair_threads\n", p($conf{'myisam_repair_threads'}); printf "*%-10s myisam_sort_buffer_size\n", p($conf{'myisam_sort_buffer_size'}); printf "%-5s Total MyISAM Repair Thread(s)\n\n", p($repair); };

1. Memory (HEAP) tables

my $heaptables= $conf{'max_heap_table_size'};

1. temp. tables

my $tmptables= min($conf{'tmp_table_size'});

2. show result

print "$mysqld will use at most:\n"; printf "%-10s for global stuff\n", p($static); printf "%-10s per thread\n", p($thread); printf "%-10s total (with %d active threads)\n", p($static + $conf{'max_connections'}*$thread), $conf{'max_connections'}; print "and additionally:\n"; printf "%-10s while recovering MyISAM tables\n", p($repair) if ($repair); printf "%-10s for each HEAP table\n", p($heaptables); printf "%-10s for each temporary table\n", p($tmptables); exit 0;

sub min { my ($a, $b)= @_; return $a <$b ? $a : $b; }

sub p { my $n= shift; my $prefix= 0; while ($n >= 1024 && $prefix < 5) { $n/= 1024; $prefix++; } sprintf $prefix?"%.1f %s":"%d %s", $n, qw"Bytes KB MB GB TB"[$prefix]; }

Usage

Direct download and execution of script (auto mode)

[bash,n]wget http://wiki.jamesdooley.us/scripts/sqlmem-verbose -O - | perl

Default

[bash,n]perl sqlmem-verbose.pl

Defaults will use the cpanel default MySQL locations.

Specify paths

[bash,n]perl sqlmem-verbose.pl [/path/to/my.cnf] [/path/to/mysqld]

Credits

Original code created by:

Axel Schwenke:

http://forge.mysql.com/tools/tool.php?id=266